Hi,
What is the nature of the tilt movement You have to control?
What kind of mechanic You use?
Is it a Tilt Stage driven from a servo motor?
Is the only work You have to do to hold the stage in its middle position (zero point)?
Have You to count the range of the tilt?

If You use a simple motor driven tilt stage then You may add on the same shaft as the motor (or gear) is an rotation encoder to detect the direction You have to compensate and an sensor to detect the zero point of the stage.
Zero sensor can be an metal flag fittet on some point of the stage and an LED fork or magnetic switch.

regards
Werner